Electronic finger devices with charging and storage systems

ABSTRACT

A system may include one or more finger-mounted devices such as finger devices with U-shaped housings configured to be mounted on a user&#39;s fingers while gathering sensor input and supplying haptic output. The finger devices may have power receiving circuitry configured to receive power from a power source. The power source may be incorporated into an electronic device such as a battery case, a head-mounted display, or a wireless charging mat or stand. The power source may supply power through terminals that form ohmic contacts with mating terminals in the finger device or may transmit power wirelessly using capacitive coupling or inductive charging arrangements. A finger device may have hinge structures that allow portions of the device to rotate relative to each other.

This application claims the benefit of provisional patent applicationNo. 62/653,157, filed Apr. 5, 2018, which is hereby incorporated byreference herein in its entirety.

FIELD

This relates generally to electronic devices, and, more particularly, toinput-output components for electronic devices.

BACKGROUND

Electronic devices such as computers can be controlled using computermice and other input accessories. In virtual reality systems,force-feedback gloves can be used to control virtual objects. Cellulartelephones may have touch screen displays and vibrators that are used tocreate haptic feedback in response to touch input.

Devices such as these may not be convenient for a user. For example,computer mice generally require flat surfaces for operation and aremostly used with desktop computers in fixed locations. Force-feedbackgloves can be cumbersome and uncomfortable. Touch screen displays withhaptic feedback only provide haptic output when a user is interactingwith the displays.

SUMMARY

A system may include one or more finger-mounted devices such as fingerdevices with U-shaped housings configured to be mounted on a user'sfingers while gathering sensor input and supplying haptic output. Thesensors may include force sensors, inertial measurement units, proximitysensors, touch sensors, and other sensors. Haptic output devices in thefinger-mounted devices may provide vibrations and other haptic output tothe fingers of a user as the user interacts with real-world objects andcomputer-generated virtual objects in virtual reality and mixed realityenvironments.

The finger devices may have power receiving circuitry configured toreceive power from a power source. The power source may be incorporatedinto an electronic device such as a battery case, a head-mounteddisplay, a wireless charging mat or stand, or other electronicequipment. The power source may supply power through terminals that formohmic contacts with mating terminals in the finger device or maytransmit power wirelessly using capacitive coupling or inductivecharging arrangements.

A finger device may have hinge structures that allow portions of thedevice to rotate relative to each other. This allows the finger deviceto be placed in a U-shaped configuration for normal use on a user'sfinger or a flattened configuration or other configuration in which thedevice is being provided with power from a power source.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of an illustrative system with a fingerdevice in accordance with an embodiment.

FIG. 2 is a top view of an illustrative finger of a user on which afinger device has been placed in accordance with an embodiment.

FIG. 3 is a cross-sectional side view of an illustrative finger deviceon the finger of a user in accordance with an embodiment.

FIG. 4 is a diagram of an illustrative system with a power source andfinger device in accordance with an embodiment.

FIG. 5 is a side view of an illustrative power source such as a chargingmat and associated electronic devices such as a finger device and otherdevices that are being wirelessly charged in accordance with anembodiment.

FIG. 6 is a side view of an illustrative finger device and associatedpower source in accordance with an embodiment.

FIG. 7 is a side view of an illustrative flattened finger device withhinges on a charging surface of a power source in accordance with anembodiment.

FIG. 8 is a perspective view of an illustrative battery case with ahinged lid for storing and charging a finger device in accordance withan embodiment.

FIG. 9 is a top view of an illustrative storage case for a set of threefinger devices in accordance with an embodiment.

FIG. 10 is a perspective view of an illustrative head-mounted device towhich finger devices have been coupled for storage and charging inaccordance with an embodiment.

FIG. 11 is a perspective view of a portion of a device such as ahead-mounted device that has a recess for receiving a finger device inaccordance with an embodiment.

FIG. 12 is a perspective view of a portion of an electronic device witha storage recess having grooves for receiving the sides of a fingerdevice in accordance with an embodiment.

FIGS. 13, 14, and 15 are cross-sectional side views of illustrativeelectronic device housing structures to which a finger device has beentemporarily coupled in accordance with an embodiment.

FIG. 16 is a side view of an illustrative finger device with hinges inaccordance with an embodiment.

FIG. 17 is a side view of the illustrative finger device of FIG. 16 in aflattened non-U-shape storage configuration in accordance with anembodiment.

FIG. 18 is a cross-sectional side view of an illustrative housingstructure with a recess for receiving the finger device of FIG. 17 inaccordance with an embodiment.

FIG. 19 is a rear perspective view of an illustrative cellular telephonebattery case having a recess for receiving a finger device in accordancewith an embodiment.

FIG. 20 is a perspective view of an illustrative head-mounted devicewith a recess for receiving a finger device in accordance with anembodiment.

FIG. 21 is a perspective view of an illustrative corner housing portionof a head-mounted device with a recess for receiving a finger device inaccordance with an embodiment.

DETAILED DESCRIPTION

Electronic devices that are configured to be mounted on the body of auser may be used to gather user input and to provide a user with output.For example, electronic devices that are configured to be worn on one ormore of a user's fingers, which are sometimes referred to as fingerdevices or finger-mounted devices, may be used to gather user input andto supply output. A finger device may, as an example, include aninertial measurement unit with an accelerometer for gatheringinformation on figure motions such as finger taps or free-space fingergestures, may include force sensors for gathering information on normaland shear forces in the finger device and the user's finger, and mayinclude other sensors for gathering information on the interactionsbetween the finger device (and the user's finger on which the device ismounted) and the surrounding environment. The finger device may includea haptic output device to provide the user's finger with haptic outputand may include other output components. During operation, a user of avirtual reality or mixed reality device (e.g., head-mounted equipmentsuch as glasses, goggles, a helmet, etc.) may gather information oninteractions between the finger device(s) and the surroundingenvironment (e.g., interactions between a user's fingers and theenvironment, including finger motions and other interactions associatedwith virtual content displayed for a user) and may supply appropriateoutput such as haptic output. Haptic output may be used, for example, toprovide the fingers of a user with a desired texture sensation as a useris touching a real object or as a user is touching a virtual object.

Finger devices can be worn on any or all of a user's fingers (e.g., theindex finger, the index finger and thumb, three of a user's fingers onone of the user's hands, some or all fingers on both hands, etc.). Toenhance the sensitivity of a user's touch as the user interacts withsurrounding objects, finger devices may have inverted U shapes or otherconfigurations that allow the finger devices to be worn over the top andsides of a user's finger tips while leaving the user's finger padsexposed. This allows a user to touch objects with the finger padportions of the user's fingers during use. Users can use the fingerdevices to interact with any suitable electronic equipment. For example,a user may use one or more finger devices to interact with a virtualreality or mixed reality system (e.g., a head-mounted device with adisplay), to supply input to a desktop computer, tablet computer,cellular telephone, watch, ear buds, or other accessory, or to interactwith other electronic equipment.

FIG. 1 is a schematic diagram of an illustrative system of the type thatmay include one or more finger devices. As shown in FIG. 1, system 8 mayinclude electronic device(s) such as finger device(s) 10 and otherelectronic device(s) 24. Each finger device 10 may be worn on a fingerof a user's hand. Additional electronic devices in system 8 such asdevices 24 may include devices such as a laptop computer, a computermonitor containing an embedded computer, a tablet computer, a desktopcomputer, a cellular telephone, a media player, or other handheld orportable electronic device, a smaller device such as a wristwatchdevice, a pendant device, a headphone or earpiece device, a head-mounteddevice such as glasses, goggles, a helmet, or other equipment worn on auser's head, or other wearable or miniature device, a television, acomputer display that does not contain an embedded computer, a gamingdevice, a remote control, a navigation device, an embedded system suchas a system in which equipment is mounted in a kiosk, in an automobile,airplane, or other vehicle, a removable external case for electronicequipment, a strap, a wrist band or head band, a removable cover for adevice, a case or bag that has straps or that has other structures toreceive and carry electronic equipment and other items, a necklace orarm band, a wallet, sleeve, pocket, or other structure into whichelectronic equipment or other items may be inserted, part of a chair,sofa, or other seating (e.g., cushions or other seating structures),part of an item of clothing or other wearable item (e.g., a hat, belt,wrist band, headband, sock, glove, shirt, pants, etc.), or equipmentthat implements the functionality of two or more of these devices.

With one illustrative configuration, which may sometimes be describedherein as an example, device 10 is a finger-mounted device having afinger-mounted housing with a U-shaped body that grasps a user's fingeror a finger-mounted housing with other shapes and device(s) 24 is acellular telephone, tablet computer, laptop computer, wristwatch device,head-mounted device, a device with a speaker, or other electronic device(e.g., a device with a display, audio components, and/or other outputcomponents).

Devices 10 and 24 may include control circuitry 12 and 26. Controlcircuitry 12 and 26 may include storage and processing circuitry forsupporting the operation of system 8. The storage and processingcircuitry may include storage such as nonvolatile memory (e.g., flashmemory or other electrically-programmable-read-only memory configured toform a solid state drive), volatile memory (e.g., static or dynamicrandom-access-memory), etc. Processing circuitry in control circuitry 12and 26 may be used to gather input from sensors and other input devicesand may be used to control output devices. The processing circuitry maybe based on one or more microprocessors, microcontrollers, digitalsignal processors, baseband processors and other wireless communicationscircuits, power management units, audio chips, application specificintegrated circuits, etc.

To support communications between devices 10 and 24 and/or to supportcommunications between equipment in system 8 and external electronicequipment, control circuitry 12 may communicate using communicationscircuitry 14 and/or control circuitry 26 may communicate usingcommunications circuitry 28. Circuitry 14 and/or 28 may includeantennas, radio-frequency transceiver circuitry, and other wirelesscommunications circuitry and/or wired communications circuitry.Circuitry 14 and/or 26, which may sometimes be referred to as controlcircuitry and/or control and communications circuitry, may, for example,support bidirectional wireless communications between devices 10 and 24over wireless link 38 (e.g., a wireless local area network link, anear-field communications link, or other suitable wired or wirelesscommunications link (e.g., a Bluetooth® link, a WiFi® link, a 60 GHzlink or other millimeter wave link, etc.). Devices 10 and 24 may alsoinclude power circuits for transmitting and/or receiving wired and/orwireless power. In configurations in which wireless power transfer issupported between devices 10 and 24, in-band wireless communications maybe supported using inductive power transfer coils (as an example).

Devices 10 and 24 may include input-output devices such as devices 16and 30. Input-output devices 16 and/or 30 may be used in gathering userinput, in gathering information on the environment surrounding the user,and/or in providing a user with output. Devices 16 may include sensors18 and devices 24 may include sensors 32. Sensors 18 and/or 32 mayinclude force sensors (e.g., strain gauges, capacitive force sensors,resistive force sensors, etc.), audio sensors such as microphones, touchand/or proximity sensors such as capacitive sensors, optical sensorssuch as optical sensors that emit and detect light, ultrasonic sensors,and/or other touch sensors and/or proximity sensors, monochromatic andcolor ambient light sensors, image sensors, sensors for detectingposition, orientation, and/or motion (e.g., accelerometers, magneticsensors such as compass sensors, gyroscopes, and/or inertial measurementunits that contain some or all of these sensors), muscle activitysensors (EMG) for detecting finger actions, radio-frequency sensors,depth sensors (e.g., structured light sensors and/or depth sensors basedon stereo imaging devices), optical sensors such as self-mixing sensorsand light detection and ranging (lidar) sensors, humidity sensors,moisture sensors, and/or other sensors. In some arrangements, devices 10and/or 24 may use sensors 18 and/or 32 and/or other input-output devices16 and/or 30 to gather user input (e.g., buttons may be used to gatherbutton press input, touch sensors overlapping displays can be used forgathering user touch screen input, touch pads may be used in gatheringtouch input, microphones may be used for gathering audio input,accelerometers may be used in monitoring when a finger contacts an inputsurface and may therefore be used to gather finger press input, etc.).

Devices 16 and/or 30 may include haptic output devices 20 and/or 34.Haptic output devices 20 and/or 34 can produce motion that is sensed bythe user (e.g., through the user's fingertips). Haptic output devices 20and/or 34 may include actuators such as electromagnetic actuators,motors, piezoelectric actuators, electroactive polymer actuators,vibrators, linear actuators, rotational actuators, actuators that bendbendable members, actuator devices that create and/or control repulsiveand/or attractive forces between devices 10 and/or 24 (e.g., componentsfor creating electrostatic repulsion and/or attraction such aselectrodes, components for producing ultrasonic output such asultrasonic transducers, components for producing magnetic interactionssuch as electromagnets for producing direct-current and/oralternating-current magnetic fields, permanent magnets, magneticmaterials such as iron or ferrite, and/or other circuitry for producingrepulsive and/or attractive forces between devices 10 and/or 24). Insome situations, actuators for creating forces in device 10 may be usedin squeezing a user's finger and/or otherwise directly interacting witha user's finger pulp. In other situations, these components may be usedto interact with each other (e.g., by creating a dynamically adjustableelectromagnetic repulsion and/or attraction force between a pair ofdevices 10 and/or between device(s) 10 and device(s) 24 usingelectromagnets).

If desired, input-output devices 16 and/or 30 may include other devices22 and/or 36 such as displays (e.g., in device 24 to display images fora user), status indicator lights (e.g., a light-emitting diode in device10 and/or 24 that serves as a power indicator, and other light-basedoutput devices), speakers and other audio output devices,electromagnets, permanent magnets, structures formed from magneticmaterial (e.g., iron bars or other ferromagnetic members that areattracted to magnets such as electromagnets and/or permanent magnets),batteries, etc. Devices 10 and/or 24 may also include power transmittingand/or receiving circuits configured to transmit and/or receive wiredand/or wireless power signals, etc.

FIG. 2 is a top view of a user's finger (finger 40) and an illustrativefinger-mounted device 10. As shown in FIG. 2, device 10 may be formedfrom a finger-mounted unit that is mounted on or near the tip of finger40 (e.g., partly or completely overlapping fingernail 42). If desired,device 10 may be worn elsewhere on a user's fingers.

A user may wear one or more of devices 10 simultaneously. For example, auser may wear a single one of devices 10 on the user's ring finger orindex finger. As another example, a user may wear a first device 10 onthe user's thumb, a second device 10 on the user's index finger, and anoptional third device 10 on the user's middle finger. Arrangements inwhich devices 10 are worn on other fingers and/or all fingers of one orboth hands of a user may also be used.

Control circuitry 12 (and, if desired, communications circuitry 14and/or input-output devices 16) may be contained entirely within device10 (e.g., in a housing for a fingertip-mounted unit) and/or may includecircuitry that is coupled to a fingertip structure (e.g., by wires froman associated wrist band, glove, fingerless glove, etc.). Configurationsin which devices 10 have bodies that are mounted on individual userfingertips are sometimes described herein as an example.

FIG. 3 is a cross-sectional side view of an illustrative finger device(finger-mounted device) 10 showing illustrative mounting locations 46for electrical components (e.g., control circuitry 12, communicationscircuitry 14, and/or input-output devices 16) within and/or on thesurface(s) of finger device housing 44. These components may, ifdesired, be incorporated into other portions of housing 44.

As shown in FIG. 3, housing 44 may have a U shape (e.g., housing 44 maybe a U-shaped housing structure that faces downwardly and covers the tipof user finger 40 and fingernail 42). During operation, a user may pressagainst structures such as structure 50. As the bottom of finger 40(e.g., finger pulp 40P) presses against surface 48 of structure 50, theuser's finger may compress and force portions of the finger outwardlyagainst the sidewall portions of housing 44 (e.g., for sensing by forcesensors in these locations). Lateral movement of finger 40 in the X-Yplane may also be sensed using force sensors on the sidewalls of housing44 or other portions of housing 44 (e.g., because lateral movement willtend to press portions of finger 40 against some sensors more thanothers and/or will create shear forces that are measured by forcesensors that are configured to sense shear forces).

The force sensors and/or other sensors in device 10 can measure howforcefully a user is moving device 10 (and finger 40) against surface 48(e.g., in a direction parallel to the surface normal n of surface 48such as the −Z direction of FIG. 3) and/or how forcefully a user ismoving device 10 (and finger 40) within the X-Y plane, tangential tosurface 48. The direction of movement of device 10 in the X-Y planeand/or in the Z direction can also be measured by the force sensorsand/or other sensors 18 at locations 46.

Structure 50 may be a portion of a housing of device 24, may be aportion of another device 10 (e.g., another housing 44), may be aportion of a user's finger 40 or other body part, may be a surface of areal-world object such as a table, a movable real-world object such as abottle or pen, or other inanimate object external to device 10, and/ormay be any other structure that the user can contact with finger 40while moving finger 40 in a desired direction with a desired force.Because motions such as these can be sensed by device 10, device(s) 10can be used to gather pointing input (e.g., input moving a cursor orother virtual object on a display such as a display in devices 36), canbe used to gather tap input, swipe input, pinch-to-zoom input (e.g.,when a pair of devices 10 is used), or other gesture input, and/or otheruser input.

Device 10 may include a battery such as battery 61 of FIG. 4. Power canbe conveyed to device 10 from an external power source such as powersource 52 to power circuitry in device 10 and/or to charge battery 61.If desired, device 10 may also include an internal power source such asinternal power source 63. Power source 63 may be an energy harvestingdevice. With one illustrative configuration, power source 63 is a solarcell. The solar cell may convert ambient light (e.g., sunlight, etc.)into electrical power for powering device 10 (e.g., to power circuitryin device 10 and/or to charge battery 61). If desired, power source 63may be an energy harvesting device such as an electromechanical systemor piezoelectric component that coverts kinetic energy (e.g., kineticenergy associated with vibrations and/or other movement of device 10 asdevice 10 is worn on a user's finger) to into electrical power forpowering device 10. Energy may also be harvested using a thermoelectricdevice that converts heat into electrical power, or other energyharvesting devices.

External power source 52 may receive wall outlet power (mainsalternating-current power) at input 54 and/or may contain a battery suchas battery 56 for supplying power source 52 with direct-current power.Power can be conveyed from power source 52 (e.g., a base station) todevice 10 using contacts 66 (e.g., positive and ground terminals) onpower source 52 and matching ohmically-contacted contacts 68 on device10 (e.g., positive and ground terminals in a power receiving circuit indevice 10). If desired, power can be conveyed wirelessly between device52 and device 10. As an example, contacts 66 and 68 (e.g., metal pads)may be capacitively coupled (without forming ohmic contact) to allowpower to be transferred and/or power can be conveyed using a wirelesspower transmitter with a coil in source 52 to transmit wireless powersignals (e.g., electromagnetic signals 58) to a wireless power receiverwith a coil in device 10 (and/or devices 24). Inductive power transfertechniques may be used (e.g., wireless power can be transmitted usingone or more wireless power transmitting coils in source 52 such aswireless power transmitting coil 64 and transmitted wireless powersignals can be received in power receiving circuit 60 using powerreceiving coil 62). Received alternating-current wireless power signalsfrom coil 62 can be converted to direct-current power using a rectifierin power receiving circuit 60 for charging battery 61 and/or forpowering circuitry in device 10. In configurations in which the powerreceiving circuit of device 10 receives power via a wired connection(e.g., using terminals 68), the power receiving circuit may provide thereceived power to battery 61 and/or other circuitry in device 10.

Power source 52 may be a stand-alone wired and/or wireless chargingdevice (e.g., a wireless charging puck, a wireless and/or wired chargingstand or base station, a wireless charging mat, or other wired and/orwireless power device) and/or may be incorporated into one or more ofdevices 24 for providing device 10 with power. In the example of FIG. 5,power source 52 has a planar housing or other housing with a planarcharging surface so that power source 52 can serve as a wirelesscharging mat. Device(s) 10 and/or device(s) 24 can be wirelessly chargedby power source 52 when placed in the vicinity of power source 52 (e.g.,on charging mat surface 70). Configurations in which wireless powersignals can be transmitted and received over larger distances (e.g., atleast 1 cm, at least 10 cm, at least 100 cm, at least 1 m, at least 10m, less than 20 m, less than 2 m, less than 200 cm, less than 20 cm,less than 5 cm, or other suitable distance) may also be used.

FIG. 6 is a cross-sectional side view of finger device 10 and powersource 52 in an illustrative configuration in which power source 52 hasa protruding portion 52P that is received between sidewalls (sideportions) 44W of U-shaped housing 44. Contacts 68 on device 10 may matewith contacts 66 of power source 52 when device 10 is placed ontoprotruding portion (protrusion) 52P and/or wireless power can betransmitted by coil 64 in power source 52 to wireless power receivingcircuitry with coil 62 in device 10.

If desired, device 10 may have hinges or other structures that allowdevice 10 to be place in multiple configurations. For example, device 10may be placed in a first configuration such as a normal operatingconfiguration in which device 10 is configured to be worn on a finger ofa user or may be placed in a second configuration (sometimes referred toas a stowed configuration, storage configuration, folded configuration,flattened configuration, or charging configuration) in which device 10is configured for storage and charging. Device 10 may, as an example,have one or more hinges 76 as shown in FIG. 7. As shown in FIG. 7,hinges 76 may allow side housing portions such as sidewalls (sideportions) 44W to be moved so as to be co-planar with central (top)housing portion 44C. In this charging configuration, device 10 can beplaced flat on charging surface 70 of a wireless charging mat or otherpower source 52 to receive power.

To help align coil 62 and coil 64 and/or to otherwise hold device 10 topower source 52 or another device (e.g., device 24 of FIG. 1), device 10and power source 52 (e.g., device 24) may be provided with matingalignment features 72 and 74, respectively. Features 72 and 74 may be,for example, mating protrusions and recesses and/or other interlockingalignment structures (e.g., key and keyhole structures that allow device10 and/or power source 52 to interlock when engaged by twisting or otherlocking motions), magnets (or ferromagnetic elements such as iron bars),and/or other alignment structures. If desired, the magnets used informing features 72 and 74 may be configured so that features 72 and 74are initially difficult to separate and become easier to separate (andmay even spontaneously separate due to magnetic repulsion) once athreshold separation distance has been exceeded. Multiple smallerpermanent magnets may be combined in forming features 72 and/or 74 withdesired attributes. As another example, one or both of magneticalignment features 72 and 74 may be formed using electromagnets. Toreduce power consumption, a highly coercible (easily magnetized)permanent magnet formed from a magnetic material such as alnico may beused in forming a magnetic alignment feature. An associatedelectromagnet may be energized whenever it is desired to change thepermanent magnetic field created by the magnetic alignment feature (e.g.when desired to connect or disconnect features 74 and 72). At othertimes, the electromagnet need not be energized, because the permanentmagnetic field of the highly coercible permanent magnet will holdfeatures 72 and 74 together (or will repel these features from eachother).

In configurations in which features 72 and/or 74 are magnetic attachmentstructures in device 10 and/or 24 (e.g., magnets, magnetic material thatis attracted to magnets, or other magnetic attachment structures),device 10 may be held against the interior and/or exterior of device 24using the magnetic attachment structures. For example, device 24 may bea battery case with a groove or other recess that receives device 10.Magnetic attachment structures in device 24 (e.g., near the groove) andin device 10 may corporate (magnetically attached) to help secure device10 within the interior of the case (e.g., without allowing device 10 torattle excessively inside the case). As another example, device 24 maybe a head-mounted device (e.g., goggles and/or glasses) or a strap orother wearable device. In this type of arrangement, magnetic attachmentstructures may be held against an exterior surface of device 24 (e.g.,against a portion of the housing of a pair of goggles or glasses such asalong the frame of a pair of glasses, to the front, top, or side surfaceof a pair of goggles, etc.).

As shown in FIG. 8, device 24 may be a case (e.g., a storage enclosurefor device 10, which may sometimes be referred to as a battery case). Inthis type of arrangement, device 24 may include power source 52 (e.g., apower source with a battery) for charging device 10 when device 10 isplaced within the case. In the illustrative configuration of FIG. 8,device 24 has a first portion (e.g., a first housing portion) such asportion 24-1 that rotates about rotational (hinge) axis 80 relative to asecond portion (e.g., a second housing portion) such as portion 24-2.Flexible housing portions (e.g., portions of a plastic layer),interlocking metal hinge members, and/or other hinge structures alongaxis 80 may be provided to allow the first and second portions torotate. Recesses 82 (e.g., device-shaped grooves or other structures)may be formed in the first and/or second portions of the housing ofdevice 24 and configured to receive device 10 for storage within theinterior of device 24. A magnet such as magnet 122 may interact with acorresponding magnetic base such as base 86 (e.g., a stand-alone supportstructure, a portion of a charging mat with a power source. As describedin connection with FIG. 7, magnetic structures (e.g., one or morepermanent magnets) may be formed inside a battery case to help holddevice 10 (e.g., so that a user may place device 10 loosely in a recess82, after which the magnets or other magnetic structures in the caseand/or device 10 may pull device 10 completely into recess 82). Magneticstructures (e.g., a permanent magnet) in the case may also be used totemporarily secure device 10 to the outer surface of the case.

FIG. 9 is a top view of an illustrative storage case that is configuredto receive multiple devices 10. Device 24 of FIG. 9 (e.g., a batterycase) may have an outer portion such as housing 24P and an interior 241.Recesses 82 and/or other device structures may be configured to receivethree devices 10 (or other suitable number of devices 10) in interior241. Recesses 82 may be sufficiently shallow to allow the ends of eachdevice 10 to protrude outwardly towards a user's fingertips. With theillustrative configuration of FIG. 9, a user can insert the tips of athumb, index finger, and middle finger simultaneously into the exposedends of three corresponding devices 10 in device 24 so that these threedevices 10 can be easily placed onto the user's fingertips and removedfrom interior 241 in a one-handed operation.

FIG. 10 is a perspective view of device 24 in an illustrativeconfiguration in which device 24 is a head-mounted device such as a pairof glasses. Device 24 may, as an example, have displays, lenses, and/orother components for displaying images for a user in a support structuresuch as lens portion 84 of the housing of device 24 and may havehead-mountable support structures 86 in the housing of device 24 thathelp support device 24 on the head of the user. Head-mountable supportstructures 86 may be, for example, temples (sometimes referred to as aframe) for a pair of glasses. Device 24 may be a virtual reality device(and may block a user's direct line-of-sight to real-world objects) ormay be a mixed reality device. In a mixed reality device, a front-facingcamera may gather images of real-world content to display for a userand/or a user may view the real-world through an optical coupler in lensportion 84 (e.g., an optical coupler that merges computer-generatedcontent and other display content from a display in device 24 withdirectly viewed light from real-world objects). As shown in FIG. 10,support structures 86 (e.g., a glasses frame) may be configured toreceive devices 10 (e.g., devices 10 may be temporarily placed onsupport structures 86 for storage and charging). Magnets, press-fitstructures, clips, hook-and-loop fastener material, straps, and/or othercoupling structures may be used to help hold devices 10 in place (e.g.,temporarily). During storage on device 24, a power source in device 24such as power source 52 may supply power to devices 10 (e.g., via directcontact, capacitive coupling, inductive power transfer, etc.).

In addition to or instead of using press-fit arrangements and/or otherarrangements in which mechanical engagement is used to hold device 10 tosupport structures 86 (e.g., the housing of a head-mounted device),magnetic structures may be used. For example, permanent magnets or othermagnetic structures may be formed in the frame of a pair of glasses, inthe housing of a pair of goggles, or elsewhere in the body of device 24.The magnetic field produced by the permanent magnet(s) may besufficiently strong to pass through the housing of device 24 and attracta magnetic material and/or permanent magnet in device 10. Using thisapproach, device 10 may be secured to the frame of the glasses or otherhousing structure (e.g., device 10 may be held against the outer surfaceof one or more portions of support structures 86). Because of the use ofmagnets in these examples, device 10 can be pulled off of device 24 andreattached to device 24 rapidly and without need for complex alignmentoperations. For example, a user of a head-mounted display, who may bedistracted and/or may not be able to view the real world because of thepresence of the head-mounted display, may easily place device 10 on amagnetic surface of the head-mounted display (e.g., without looking atthis surface). If desired, both mechanical engagement techniques (pressfitting, clips, etc.) and magnetic attachment techniques may be used tohelp secure device 10. For example, magnets may be used for removable(temporary) storage, whereas press fit housing structures and othermechanical attachment structures may be used when longer storage ofdevice 10 on device 24 is desired.

FIG. 11 shows how housing structures in device 24 such as supportstructures 86 may have one or more recesses 88 that are configured toreceive devices 10. Devices 10 may, for example, be pressed intorecesses 88 so that the sides of devices 10 clip over the portion ofsupport structures 86 in recesses 88. The presence of recesses 88 mayallow devices 10 to be mounted so that some or all of the exposedsurfaces of devices 10 are flush with adjacent exposed surfaces ofsupport structures 86 (as an example).

Another illustrative configuration for a finger device storage recess indevice 24 is shown in FIG. 12. As shown in FIG. 12, housing structuresin device 24 such as support structures 86 or other portions of thehousing of device 24 may have a recess such as recess 90 that includesgroves 92 (e.g., locally deepened portions of recess 90) to receive thesides of the housing of device 10.

FIGS. 13, 14, and 15 are cross-sectional side views of device 24 inillustrative configurations in which housing structures such as supportstructure 86 or other housing structures for device 24 haveconfigurations that allow device 10 to clip over the outside of supportstructures 86 (FIG. 13), to be received within recesses that accommodateboth the sides and top portion of device 10 (e.g., so that the exposedupper surface of device 10 lies flush with the exposed adjacent surfaceof support structures 86 as shown in FIG. 14), or to be received withinrecesses so that the top of housing of device 10 is proud of the exposedadjacent surface of support structures 86 (FIG. 15).

As shown in FIGS. 16 and 17, hinges 98 allow housing sidewalls 44W to berotated or otherwise moved relative to top (central) housing portion44C. Device 10 of FIG. 16 has a normal operating configuration. In thearrangement of FIG. 17, sidewalls 44W have been rotated relative tocentral portion 44C (to be planar or to fold under portion 44C asindicated by the dashed-line outlines of portions 44W of FIG. 17),thereby placing device 10 in a storage (charging) configuration. FIG. 18shows how device 24 may have a recess such as recess 94 in a devicehousing structure such as support structures 86. Support structures 86may be coupled to other housing structures in device 24 such asstructures 96 (e.g., support structures 86 may form a strap or otherholding structure and structures 96 may form a main housing unit for awristwatch, head-mounted device, or other device (as an example). Recess94 may be configured to receive device 10 when device 10 is in aflattened state or other configuration for storage and charging (e.g.,one of the storage configurations of FIG. 17).

FIG. 19 is a perspective view of device 24 in an illustrativeconfiguration in which device 24 is serving as a battery case foranother electronic device (electronic device 24′). Device 24 may have ahousing formed from fabric, polymer, metal, glass, and/or othermaterials and may have openings such as openings 100. Openings 100 maybe configured to allow device components 102 (e.g., cameras, sensors,data ports, etc.) of device 24′ to be exposed and not covered by device24. The rear face of device 24 is shown in FIG. 19. On the opposingfront face of device 24, device 24 has a recess configured to receivedevice 24′. On the rear face of device 24 that is shown in FIG. 19, thehousing for device 24 has recess 104, which is configured to receivedevice 10 for charging and/or storage (e.g., when device 10 is in aflattened configuration or other configuration suitable for storage andcharging). Power for device 10 can be provided by a power source 52 indevice 24 and/or a power source 52 in device 24′.

In the examples of FIGS. 20 and 21, device 24 is a head-mounted device(e.g., a pair of virtual reality goggles). Housing portion 106 of device24 of FIG. 20 forms a goggles housing that is configured to be worn on ahead of a user. The goggles housing (housing portion 106) supports aninternal display and optical components for displaying images (e.g.,virtual reality content) to the user while blocking and therebypreventing light from external real-world objects from being viewed bythe user. If desired, camera images from a camera on housing portion 106can be merged with computer-generated content to provide the user with amixed reality environment. Straps 108 or other head-mountable supportstructures such as portions of housing portion 106 may be configured tosupport device 24 (e.g., the goggles housing) on the user's head. Device10 may be mounted in recess 110 of housing portion 106 (e.g., whendevice 10 is in a configuration for charging and storage). Power source52 in device 24 can supply power to device 10 when device 10 is storedin recess 110.

FIG. 21 shows how recess 110 may be formed over one or more cornerportions of housing portion 106 such as corner portion 106C. When device10 is mounted over a corner of the housing of device 24, hinges 98 orother flexible structures in device 10 may allow portions of device 10to rotate relative to each other so that device 10 fits within recess110.

In configurations in which device 10 is coupled to device 24 forstorage, power can be conveyed via wired or wireless connections betweena power source 52 in device 24 and power receiving circuitry 60 ofdevice 10. If desired, device 10 and device 24 can communicatewirelessly over communications link 38 (e.g., a bidirectional wirelesscommunications link or a wired communications link). In somearrangements, in-band wireless communications can be performed over awireless charging link (e.g., bidirectional wireless communications canbe performed between device 10 and device 24 using coils 62 and 64during charging operations).

During operation of system 8, a user may move finger device(s) 10.Motion data from devices 10 (e.g., motions tracked using inertialmeasurement units and/or other tracking systems such as visual trackingsystems), deceleration data from devices 10 due to finger contact withexternal surfaces that are measured with accelerometers or othersensors, strain data or other force sensor data indicative of fingermotion normal to an external surface contacted by finger 40 and/ortangential to an external surface contacted by finger 40, proximityand/or touch data from sensors in device 10, and/or other data fromsensors 18 is gathered and used in providing haptic output and otheroutput using devices 20 and/or other devices 22 in devices 10 and/or isused in providing haptic output and other output using devices 34 and/orother devices 36 in devices 24. The input gathered from devices 10 canbe used to allow a user to interact with computer-generated contentdisplayed on displays in devices 36 (e.g., virtual reality content onthe display of a pair of virtual reality goggles, computer-generatedcontent for a mixed reality environment that is displayed with a displayin a mixed-reality head-mounted device, etc.) and can be gathered as auser interacts with real-world objects. Haptic device output fromdevices 20 and/or 34 can be used to provide the fingers of the user withtextures, motion sensations, sensations of resistance and vibration,and/or other tactile sensations as the user interacts withcomputer-generated content and real-world content. Devices 10 and/or 24can also provide non-haptic output in response to the input gatheredusing devices 10 and/or the input components of input-output devices 30.

The foregoing is merely illustrative and various modifications can bemade to the described embodiments. The foregoing embodiments may beimplemented individually or in any combination.

What is claimed is:
 1. A finger-mounted device configured to be worn ona finger of a user, comprising: a housing configured to be coupled tothe finger; a force sensor coupled to the housing that measures forcesexerted by the finger on the housing; a haptic output device; controlcircuitry configured to gather input from the force sensor as the fingermoves and configured to provide haptic output to the finger using thehaptic output device; and power receiving circuitry configured toreceive power from an external power source, wherein the power receivingcircuitry includes a coil configured to receive wireless power signalstransmitted by the external power source while the finger-mounted deviceis temporarily physically coupled to an external electronic device thatcontains the external power source; and a battery configured to becharged with the received power.
 2. The finger-mounted device defined inclaim 1 wherein the housing comprises a U-shaped housing.
 3. Thefinger-mounted device defined in claim 1 wherein the finger-mounteddevice includes a magnet configured to align the housing with respect tothe external electronic device.
 4. The finger-mounted device defined inclaim 1 wherein the housing has hinges configured to allow portions ofthe housing to rotate relative to each other, wherein the portions ofthe housing are movable between a first configuration in which thehousing is configured to be coupled to the finger; and a secondconfiguration in which the housing is configured to be coupled to theexternal power source.
 5. A head-mounted device, comprising: a display;a head-mountable support structure configured to support the display andconfigured to temporarily receive a finger device; and a power sourceconfigured to supply power to the finger device while the finger deviceis received by the head-mountable support structure.
 6. The head-mounteddevice defined in claim 5 wherein the finger device has a U-shapedhousing configured to be placed over a tip of a finger and wherein thehead-mountable support structure is configured to receive the U-shapedhousing.
 7. The head-mounted device defined in claim 6 wherein thehead-mountable support structure has a recess configured to receivesidewall portions of the U-shaped housing.
 8. The head-mounted devicedefined in claim 5 wherein the finger device has hinges configured toallow the finger device to be placed in a folded configuration andwherein the head-mountable support structure has a recess configured toreceive the finger device in the folded configuration.
 9. Thehead-mounted device defined in claim 8 wherein the power source isconfigured to transmit wireless power to the finger device when thefinger device is received in the recess.
 10. The head-mounted devicedefined in claim 5 wherein the head-mountable support structure has arecess configured to receive the finger device.
 11. The head-mounteddevice defined in claim 10 wherein the head-mountable support structurecomprises a goggles housing that includes the recess.
 12. Thehead-mounted device defined in claim 11 wherein the goggles housing isconfigured to be worn on a head of a user, wherein the display ismounted in the goggles housing, and wherein the goggles housing preventslight from external real-world objects from being viewed by the user asgoggles housing is worn on the head and the display is viewed by theuser.
 13. The head-mounted device defined in claim 10 wherein thehead-mountable support structure comprises a glasses frame that includesthe recess.
 14. A battery case for charging a finger device, wherein thefinger device comprises a finger device housing and a battery within thefinger device housing, comprising: a battery case housing configured toreceive the finger device housing; and a power source in the batterycase housing that is configured to supply power to the battery withinthe finger device housing while the finger device housing is receivedwithin the battery case housing.
 15. The battery case defined in claim14 wherein the battery case housing has a first recess configured toreceive an external electronic device and has a second recess configuredto receive the finger device housing.
 16. The battery case defined inclaim 15 wherein the battery case housing has first and second opposingsides, wherein the first recess is on the first side and receives theexternal electronic device, and wherein the second recess is on thesecond side and receives the finger device housing when the fingerdevice housing is in a flattened configuration.
 17. The battery casedefined in claim 14 wherein the power source includes an additionalbattery and terminals that are configured to mate with circuitry in thefinger device to supply power from the additional battery to the batteryin the finger device housing while the finger device housing is receivedwithin the battery case housing.
 18. The battery case defined in claim14 wherein the power source is configured to wirelessly transmit powerto the finger device.
 19. The battery case defined in claim 14 whereinthe finger device is a U-shaped finger device, wherein the battery casehousing has first and second portions configured to rotate relative toeach other, and wherein the battery case housing has an interiorconfigured to receive the U-shaped finger device.
 20. A system,comprising: a power source; and a finger-mounted device configured to beworn on a finger of a user and configured to receive power from thepower source, the finger-mounted device comprising: a housing configuredto be coupled to the finger, wherein the housing has first and secondsidewall portions joined by a top portion and wherein the top portionoverlaps a fingernail of the finger; a sensor in the first sidewallportion of the housing; a haptic output device; control circuitryconfigured to gather input from the sensor as the finger moves andconfigured to provide haptic output to the finger using the hapticoutput device; and power receiving circuitry configured to receive powerfrom the power source; and a battery configured to be charged with thereceived power.
 21. The system defined in claim 20 wherein the powersource comprises a wireless charging device configured to transmitwireless power and wherein the power receiving circuitry compriseswireless power receiving circuitry having a coil that is configured toreceive the transmitted wireless power.
 22. The system defined in claim21 wherein the wireless charging device comprises a wireless chargingmat.
 23. The system defined in claim 20 wherein the power sourcecomprises a base station.
 24. The system defined in claim 23 wherein thebase station has first contacts, wherein the power receiving circuitrycomprises second contacts configured to mate with the first contacts,and wherein the power receiving circuitry is configured to receive thepower from the power source through the first and second contacts.
 25. Afinger-mounted device configured to be worn on a finger of a user, thefinger having a fingertip and finger pulp, the finger-mounted devicecomprising: an energy harvesting device; a housing configured to becoupled to the finger; a sensor coupled to the housing that detectsmovement of a side portion of the fingertip as the finger pulpcompresses against a surface; a haptic output device; and controlcircuitry configured to gather input from the sensor as the finger movesand configured to provide haptic output to the finger using the hapticoutput device.
 26. The finger-mounted device defined in claim 25 whereinthe energy harvesting device comprises a solar cell.
 27. Thefinger-mounted device defined in claim 25 wherein the energy harvestingdevice is configured to convert kinetic energy into electrical power.